US4770835A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for molding using a dual solid flowable polymer system
Assignee: RTX Corp
•
Filing: 1986-09-10
•
Granted: 1988-09-13
•
Expires: 2006-09-10
Abstract
Abstract A method of molding an article utilizing two types of solid flowable particulate polymer pressurizing media wherein one medium is protected from thermal degradation by a second medium. The method comprises disposing an article precursor within a pressure vessel and disposing a first solid flowable polymer medium that is substantially thermally stable at temperatures in excess of about 316° C. so that it is capable of transferring a substantially uniform, predetermined medium pressure to the surface of the article precursor. A second solid flowable polymer medium is disposed so that it is capable of transferring a substantially uniform, predetermined medium pressure to the first polymer medium. The second medium is caused to produce a substantially uniform medium pressure so that said pressure is transferred to the surface of the article precursor and the article precursor is exposed to temperatures in excess of about 316° C. The second polymer is protected from thermal degradation by the thermal stability and high insulative capability of the first polymer medium.
Inventors
- 👤 Robert V. Kromrey
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 16:11
CPC Classifications
B; B30; B30B; B30B11/00; B30B11/001; B29; B29C; B29C35/00; B29C35/02; B29C43/00; B29C43/02; B29C43/10; B29C70/00; B29C70/04; B29C70/06; B29C70/10; B29C70/12; B29C70/28; B29C70/40; B29C70/42; B29C70/44; B29C43/12
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
187 words
A method of molding an article from an article precursor at elevated temperatures and pressures comprising: (a) disposing said article precursor within a pressure vessel; (b) disposing a first solid flowable particulate polymer medium that is substantially thermally stable at temperatures in excess of about 316° C. so that said first polymer is capable of transferring a substantially uniform, predetermined medium pressure to the surface of said article precursor; (c) disposing a second solid flowable particulate polymer medium that is less thermally stable than said first solid flowable polymer medium so that said second polymer is capable of causing a substantially uniform, predetermined mediium pressure to the first solid flowable particulate polymer medium; (d) causing said second medium to produce a substantially uniform predetermined medium pressure to be applied to said first solid flowable polymer medium so that said first solid flowable polymer medium applies a substantially uniform, predetermined medium pressure to the surface of the article precursor; and (e) exposing said article precursor to temperature in excess of about 316° C.; whereby said second polymer medium is protected from thermal degradation by said first polymer medium.
Claim 2
Independent Claim
187 words
A method of molding an article from an article precursor at elevated temperatures and pressures comprising: (a) disposing said article precursor within a pressure vessel; (b) disposing a first solid flowable particulate polymer medium that is substantially thermally stable at temperatures in excess of about 316° C. so that said first polymer is capable of transferring a substantially uniform, predetermined medium pressure to the surface of said article precursor; (c) disposing a second solid flowable particulate polymer medium that is less thermally stable than said first solid flowable polymer medium so that said second polymer is capable of causing a substantially uniform, predetermined mediium pressure to the first solid flowable particulate polymer medium; (d) causing said second medium to produce a substantially uniform predetermined medium pressure to be applied to said first solid flowable polymer medium so that said first solid flowable polymer medium applies a substantially uniform, predetermined medium pressure to the surface of the article precursor; and (e) exposing said article precursor to temperature in excess of about 316° C.; whereby said second polymer medium is protected from thermal degradation by said first polymer medium.
Claim 3
Dependent Claim
47 words
The method as recited in claim 1 wherein said first polymer medium comprises a solid, flowable, particulate silicone rubber having a nominal flow rate of at least 0.6 gram/second through a 1.1 cm diameter pipe 7.6 cm long under applied pressure of 10.34 MPa at room temperature.
Claim 4
Dependent Claim
23 words
The method as recited in claim 2 wherein said first polymer medium comprises a vinylmethylsiloxanedimethylsiloxane having about 40% to about 60% vinyl content.
Claim 5
Dependent Claim
47 words
The method as recited in claim 1 wherein said second polymer medium comprises a solid, flowable, particulate silicone rubber having a nominal flow rate of at least 0.6 gram/second through a 1.1 cm diameter pipe 7.6 cm long under applied pressure of 10.34 MPa at room temperature.
References Cited (Backward Citations)
US3556201A
Cited
DE2134168A1
Cited
US3843601A
Cited
US4167430A
Cited
US4264556A
Cited
US4388263A
Cited
US4547337A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1991-09-13 | 1992-03-14 | 1992-09-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-09-13 | 1996-03-14 | 1996-09-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-09-13 | 2000-03-14 | 2000-09-13 | $7700.00 | Window Closed / Lapsed |